uuencode, uudecode - Encode/decode a binary file for mailing


uuencode source target

uudecode file


Uuencode and uudecode are used to send binary files via uucp (or other) mail. This combination can be used over indirect mail links.

Uuencode takes the named source file and produces an encoded version to the target file. The encoding uses only printing ASCII characters, and includes a mode of 644 and the target name for recreation on the remote system.

Uudecode reads an encoded file, strips off any leading and trailing lines added by mailers, and recreates the original file with the specified mode and name.

The encode file has an ordinary text form and can be edited by any text editor to change the mode or remote name.


The file is expanded by 35% (3 bytes become 4 plus control information) causing it to take longer to transmit.

Not all file information is retained, therefore it is suggested that files first be archived with compression to make up for the uuencoding expansion before being encoded.

The user on the remote system who is invoking uudecode must have write permission on the specified file.

See Also

par(C), rcp(NET), unpar(C)